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GSE41296
Homo sapiens
120 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Gene expression analysis has been established as a tool for the characterization of genotoxic mechanisms of chemical mutagens. This approach has been shown to differentiate between DNA reactive genotoxins and non-DNA reactive or indirectly-acting genotoxins. In this context, it has been suggested that expression analysis is capable of distinguishing compounds that cause DNA damage from those that interfere with mitotic spindle function. Formaldehyde (FA) is known to be a DNA-reactive substance which mainly induces chromosomal damage in cultured mammalian cells. However, there has been concern that FA might also act as an aneugen (i.e., induce aneuploidy) but recent cytogenetic studies did not support this assumption. To further characterize FA's genotoxic mode of action, we now used gene expression profiling as a molecular tool to differentiate between clastogenic and aneugenic activity. TK6 cells were exposed to FA for 4 and 24 h and changes in gene expression were analyzed using a whole-genome human microarray. Results were compared to the expression profiles of two DNA-damaging clastogens (methyl methanesulfonate [MMS] and ethyl methanesulfonate [EMS]) and two aneugens (colcemid [COL] and vincristine [VCR]). The gene expression profiles indicated that clastogens and aneugens induce discriminable gene expression patterns. The expression profile of FA showed more similarities to clastogens than to aneugens. Hierarchical clustering analysis as well as several class prediction algorithms revealed a much closer relationship of FA with clastogens than with aneugens. A pathway analysis of differentially regulated genes also demonstrated an overall better agreement of FA with clastogens than with aneugens. Altogether, the results of this study revealed great similarities in gene expression in response to FA and clastogens but did not support an aneugenic activity of FA.
Publication Title
Characterization of formaldehyde's genotoxic mode of action by gene expression analysis in TK6 cells.
Sample Metadata Fields
Cell line, Treatment
View Samples- Homo sapiens
- 92 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
41 volunteers (male non-smokers) were exposed to formaldehyde (FA) vapors for 4 h per day over a period of 5 working days under strictly controlled conditions. For each exposure day, different exposure concentrations were used in a random order ranging from 0 up to 0.7 ppm. At concentrations of 0.3 ppm and 0.4 ppm, four peaks of 0.6 or 0.8 ppm for 15 min each were applied. During exposure, subjects had to perform bicycle exercises (about 80 W) four times for 15 min. Blood samples, exfoliated nasal mucosa cells and nasal biopsies were taken before the first and after the last exposure. Nasal epithelial cells were additionally sampled 1, 2 and 3 weeks after the end of the exposure period. The alkaline comet assay, the sister chromatid exchange (SCE) test and the cytokinesis-block micronucleus test (CBMNT) were performed with blood samples. The micronucleus test (MNT) was also performed with exfoliated nasal mucosa cells. The expression (mRNA level) of the GSH-dependent formaldehyde dehydrogenase (FDH, identical to alcohol dehydrogenase 5; ADH5; EC 1.2.1.46) was measured in blood samples by quantitative real-time RT-PCR with TaqMan probes. DNA microarray analyses using a full-genome human microarray were performed on blood samples and nasal biopsies of selected subgroups with the highest FA exposure at different days. None of the tests performed showed a biologically significant effect related to FA exposure. Under the experimental conditions of this study, inhalation of FA did not lead to genotoxic effects in peripheral blood cells and nasal mucosa and had no effect on the expression of the FDH gene. Inhalation of FA also did not cause biologically relevant alterations in the expression of genes in a microarray analysis with nasal biopsies and peripheral blood cells.
Publication Title
Assessment of genotoxic effects and changes in gene expression in humans exposed to formaldehyde by inhalation under controlled conditions.
Sample Metadata Fields
Sex, Specimen part, Treatment, Subject
View Samples- Homo sapiens
- 36 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Using various exposure conditions, we studied the induction of DNA-protein crosslinks (DPX) by formaldehyde (FA) and their removal in primary human nasal epithelial cells (HNEC). DPX were indirectly measured by the alkaline comet assay as the reduction of gamma ray induced DNA migration. DPX are the most relevant primary DNA alterations induced by FA and the comet assay is a very sensitive method for the detection of FA-induced DPX. In parallel experiments, we investigated changes in gene expression by using a full genome human microarray. After a single treatment with FA (50 to 200 M), concentration and time-dependent changes in gene expression were seen under conditions that also induced genotoxicity. Repeated treatments with low FA concentrations (20 and 50 M) did not lead to a significant induction of DPX but repeated treatments with 50 M FA changed the expression of more than 100 genes. Interestingly, the expression of genes involved in the main pathway for FA detoxification and the repair of DPX were not specifically enhanced. A high degree of overlap was seen among the pattern of gene changes induced by FA in HNEC in comparison to recently published array studies for nasal epithelial cells from rats exposed to FA in vivo. Our results suggest that HNEC are a suited in vitro model for the characterization of FA-induced toxicity and the relationship between genotoxic and other cytotoxic effects.
Publication Title
Gene expression changes in primary human nasal epithelial cells exposed to formaldehyde in vitro.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 28 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Large cell lymphomas of the gastrointestinal tract are currently regarded as diffuse large B-cell lymphomas despite a more favourable clinical outcome and a lower aggressiveness compared to other nodal and extranodal DLBCL. We compared gene expression profiles of 28 gastrointestinal marginal zone B-cell lymphomas and variants with several other B-cell lymphoma entities such as Burkitts lymphoma, nodal DLBCL, follicular lymphoma, mantle cell lymphoma, primary mediastinal B-cell lymphoma and normal B-cell populations. Based on a subset of NF-kappaB target genes, partitioning and hierarchical cluster algorithms were used which led to comparable results. The different B-cell subsets, the Burkitts lymphoma, and the small cell lymphomas formed distinct groups, respectively. The DLBCL were subdivided into one group containing only DLBCL samples, one subset clustered together with the PMBL samples, and another one together with the blastic variants of MZBL. These results implicate that extranodal blastic MZBL represent a distinct subgroup of DLBCL.
Publication Title
Comparative gene-expression profiling of the large cell variant of gastrointestinal marginal-zone B-cell lymphoma.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 24 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
The clathrin-binding domain of CALM and the OM-LZ domain of AF10 are sufficient to induce acute myeloid leukemia in mice.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 20 Downloadable Samples
- Affymetrix Human Exon 1.0 ST Array [probe set (exon) version (huex10st)
Description
We used Affymetrix GeneChip Human Exon 1.0 ST Arrays to identify alternative splicing events in 15 samples of PDAC compared to 6 non-tumor samples. Several commercial and open source software approaches for the analysis of differential splicing were tested and a subset of overlapping results was validated using RT-PCR and sequencing. Splicing variants could be validated in several genes closely related to cancer. Pathway analysis of genes predicted to be alternatively spliced revealed an enrichment of genes in categories closely related to cell-cell interactions and kinase activity.
Publication Title
No associated publication
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 20 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
FOXO1 is highly expressed in normal B cells and in most types of non-Hodgkinl lymphoma. In Hodgkin and Reed-Sternberg cells of classical Hodgkin lymphoma(cHL) expression of FOXO1 is low or absent. We overexpressed constitutively active mutant of FOXO1 fused in frame with estrogen receptor ligand-binding domain (FOXO1(3A)ER), which can be activated by 4-Hydroxytamoxifen (4-OHT), in cHL cell lines KM-H2 and L428. Activation of the FOXO1 with 4-OHT resulted in inhibition of proliferation and apoptosis. Using gene-expression array we found that FOXO1 activates transcription of known and potential tumor suppressor genes: CDKN1B, PMAIP1, BCL2L11, TNFSF10, FBXO32, CBLB). Of note, FOXO1 repressed transcription of several cytokines and cytokine receptors, which are known tobe involved in pathogenesis of cHL (e.g. CCL5, CXCR5, TNFRSF8). Taken togather our data indicate important role of FOXO1 repression in pathogenesis of cHL.
Publication Title
FOXO1 repression contributes to block of plasma cell differentiation in classical Hodgkin lymphoma.
Sample Metadata Fields
Specimen part, Cell line, Treatment
View Samples- Mus musculus
- 14 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Canonical IKK/NF-B signaling is a master regulator of inflammation and innate immunity and has been implicated in the pathogenesis of T1D. To investigate the impact of NF-B activation on -cell homeostasis and diabetes development, we generated a transgenic gain-of-function mouse model allowing conditional NF-B activation via expression of IKK2-CA (constitutively active IKK2 allele) in -cells using the tetracycline-regulated gene expression system. Pdx-1-tTA (knockin model generating Pdx-1 haploinsufficiency) driver mice were used for -cell specific transgene expression. Double transgenic IKK2-CA-pdx-1 mice develop a full-blown immune-mediated diabetes.To identify gene expression changes underlying this diabetes development pancreatic islets of diabetic IKK2-CA-Pdx-1, PDX-1 +/- and control mice were prepared and isolated total RNA was used for microarray analysis.
Publication Title
Long-term IKK2/NF-κB signaling in pancreatic β-cells induces immune-mediated diabetes.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 9 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
We found that 5-Aza-dC/decitabine induces various prosurvival pathways (JAK-STAT-, NFkB-, MEK/ERK- and PI3K/AKTpathway) in cHL cell lines. Inhibition of these pathways with specific small molecular weight inhibitors potentiates the antitumor effect of 5-Aza-dC.
Publication Title
Activation of oncogenic pathways in classical Hodgkin lymphoma by decitabine: A rationale for combination with small molecular weight inhibitors.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 3 Downloadable Samples
- Affymetrix Human Gene 2.0 ST Array (hugene20st)
Description
In previous studies, miR-1825 has been found to be downregulated in the serum of familial and sporadic patients with amyotrophic lateral sclerosis (ALS). In this study, we aim to identify the target mRNAs of miR-1825 using a combination of proteomic and transcriptomic approaches.
Publication Title
Dysregulation of a novel miR-1825/TBCB/TUBA4A pathway in sporadic and familial ALS.
Sample Metadata Fields
Cell line
View Samples